Some translations for this key verse and advice from the Bhagavad Gita on the use of self-inquiry & self-attentiveness as a means to attain unity and liberation:
Bhagavad Gita - Chapter 6, Verse 24, 25.
सङ्कल्पप्रभवान्कामांस्त्यक्त्वा सर्वानशेषत: |
मनसैवेन्द्रियग्रामं विनियम्य समन्तत: || 24||
शनै: शनैरुपरमेद्बुद्ध्या धृतिगृहीतया |
आत्मसंस्थं मन: कृत्वा न किञ्चिदपि चिन्तयेत् || 25||
saṅkalpa-prabhavān kāmāns tyaktvā sarvān aśheṣhataḥ
manasaivendriya-grāmaṁ viniyamya samantataḥ
śhanaiḥ śhanair uparamed buddhyā dhṛiti-gṛihītayā
ātma-sansthaṁ manaḥ kṛitvā na kiñchid api chintayet
SYNONYMS
śanaiḥ—gradually; śanaiḥ—step by step; uparamet—hesitated; buddhyā—by intelligence; dhṛti-gṛhītayā—carrying the conviction; ātma-saṁstham—placed in Transcendence; manaḥ—mind; kṛtvā—doing so; na—nothing; kiñcit—anything else; api—even; cintayet—be thinking of.
Some English translations (verse 25):
(1 - Prabhupada)
Gradually,
step by step, with full conviction, one should become situated in
trance by means of intelligence, and thus the mind should be fixed on
the Self alone and should think of nothing else.
(2 - Fuerstein)
Making the mind settled in the Self by holding the wisdom-faculty steadfast, he should not think of anything.
(3 - Muktananda)
Completely renouncing all desires arising from thoughts of the world,
one should restrain the senses from all sides with the mind. Slowly and
steadily, with conviction in the intellect, the mind will become fixed
in God alone, and will think of nothing else.
(4 - Sri Ramana Maharshi)
Fix the mind [your attention] in [or on] ātman
[yourself]; do not think even the slightest of anything else at all.